The top surface of the panel may be adapted to receive a preselected finishing material including carpeting, vinyl...http://www.google.com/patents/US4843781?utm_source=gb-gplus-sharePatent US4843781 - Composite access floor panelAdvanced Patent SearchPublication numberUS4843781 APublication typeGrantApplication numberUS 07/122,520Publication dateJul 4, 1989Filing dateNov 20, 1987Priority dateJul 1